You cannot prevent people to not give out secrets.
Yet, in public this sounds like "ok, I can't tell you here, let's go to a private discussion, there I can tell you" in order to "help" them is ... well.
It's not basically against the rules to give out spoilers, yet it is in fact not appreciated... simply because you take away the fun from the game for n00bs. Why? It's like reading a book where you already know the story to the end. Most people would put it away, since the thrill is gone...
Yet it is not something I will punish. I simply strongly dislike it.